High-density lipoprotein binding to guinea-pig hepatic membranes. Comparison of guinea-pig and human ligands.
Human and guinea-pig apo-E-free HDL were incubated with isolated guinea-pig hepatic membranes at 4 and 37 degrees C to determine the effects of temperature and heterologous systems on the equilibrium parameters of HDL binding. Receptor mediated HDL binding was highest at 37 degrees C for both lipoproteins. At 4 degrees C, a higher affinity constant (Kd) was observed when guinea-pig HDL was the ligand relative to human HDL; in contrast, both HDL preparations had similar Kd values at 37 degrees C. Calculated binding and receptor number (Bmax) were higher at both temperatures when guinea-pig HDL was the ligand. These results demonstrate a significant species difference in HDL binding to hepatic membrane which is partially temperature-dependent.
Fernandez
M L
ML
Department of Nutrition & Food Science, University of Arizona, Tucson 85721.
McNamara
D J
DJ
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D006801:Humans; D008024:Ligands; D008075:Lipoproteins, HDL / Q000302:isolation & purification / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*
D008024:Ligands; D008075:Lipoproteins, HDL